New method of creation of a rearrangeable local Coulomb potential profile and its application for investigations of local conductivity of InAs nanowires

We present a new technique to create a reconfigurable Coulomb potential profile. The potential profile on the sample surface covered with residual polymethyl methacrylate (PMMA) layer as charge accumulation substance is performed with a low DC voltage applied to conductive probe tip of scanning microscope. To characterize the resulted Coulomb potential profile Kelvin probe technique is used. The effectiveness of this method is demonstrated by performing measurements of the local conductivity of InAs quantum wires. These investigations revealed an inhomogeneous conductivity of the wires and the formation of a potential barrier in the wire at the contact pad interface when the electronic system of the wire is depleted.

► AFM conductive tip is used to create of reconfigurable Coulomb potential profile in thin residual PMMA layer.
► Resolution and stability of resulted profile are investigated.
► Application of this technique is applied to study local conductivity of InAs nanowires.
► It is shown that the InAs nanowire becomes essentially inhomogeneous when electronic system is depleted.